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#ifndef _GPXE_TCP_H
#define _GPXE_TCP_H
/** @file
*
* TCP protocol
*
* This file defines the gPXE TCP API.
*
*/
#include <stddef.h>
#include <gpxe/list.h>
#include <gpxe/tcpip.h>
#include <gpxe/pkbuff.h>
#include <gpxe/retry.h>
struct tcp_connection;
/**
* TCP operations
*
*/
struct tcp_operations {
/*
* Connection closed
*
* @v conn TCP connection
* @v status Error code, if any
*
* This is called when the connection is closed for any
* reason, including timeouts or aborts. The status code
* contains the negative error number, if the closure is due
* to an error.
*
* Note that acked() and newdata() may be called after
* closed(), if the packet containing the FIN also
* acknowledged data or contained new data. Note also that
* connected() may not have been called before closed(), if
* the close is due to an error.
*/
void ( * closed ) ( struct tcp_connection *conn, int status );
/**
* Connection established (SYNACK received)
*
* @v conn TCP connection
*/
void ( * connected ) ( struct tcp_connection *conn );
/**
* Data acknowledged
*
* @v conn TCP connection
* @v len Length of acknowledged data
*
* @c len is guaranteed to not exceed the outstanding amount
* of unacknowledged data.
*/
void ( * acked ) ( struct tcp_connection *conn, size_t len );
/**
* New data received
*
* @v conn TCP connection
* @v data Data
* @v len Length of data
*/
void ( * newdata ) ( struct tcp_connection *conn,
void *data, size_t len );
/**
* Transmit data
*
* @v conn TCP connection
* @v buf Temporary data buffer
* @v len Length of temporary data buffer
*
* The application should transmit whatever it currently wants
* to send using tcp_send(). If retransmissions are required,
* senddata() will be called again and the application must
* regenerate the data. The easiest way to implement this is
* to ensure that senddata() never changes the application's
* state.
*
* The application may use the temporary data buffer to
* construct the data to be sent. Note that merely filling
* the buffer will do nothing; the application must call
* tcp_send() in order to actually transmit the data. Use of
* the buffer is not compulsory; the application may call
* tcp_send() on any block of data.
*/
void ( * senddata ) ( struct tcp_connection *conn, void *buf,
size_t len );
};
#if USE_UIP
/**
* A TCP connection
*
*/
struct tcp_connection {
/** Address of the remote end of the connection */
struct sockaddr_in sin;
/** Operations table for this connection */
struct tcp_operations *tcp_op;
};
extern void tcp_connect ( struct tcp_connection *conn );
extern void tcp_send ( struct tcp_connection *conn, const void *data,
size_t len );
extern void tcp_kick ( struct tcp_connection *conn );
extern void tcp_close ( struct tcp_connection *conn );
#else
#define TCP_NOMSG ""
#define TCP_NOMSG_LEN 0
/* Smallest port number on which a TCP connection can listen */
#define TCP_MIN_PORT 1
/* Some PKB constants */
#define MAX_HDR_LEN 100
#define MAX_PKB_LEN 1500
#define MIN_PKB_LEN MAX_HDR_LEN + 100 /* To account for padding by LL */
/**
* TCP states
*/
#define TCP_CLOSED 0
#define TCP_LISTEN 1
#define TCP_SYN_SENT 2
#define TCP_SYN_RCVD 3
#define TCP_ESTABLISHED 4
#define TCP_FIN_WAIT_1 5
#define TCP_FIN_WAIT_2 6
#define TCP_CLOSING 7
#define TCP_TIME_WAIT 8
#define TCP_CLOSE_WAIT 9
#define TCP_LAST_ACK 10
#define TCP_INVALID 11
/**
* A TCP connection
*/
struct tcp_connection {
struct sockaddr_tcpip peer; /* Remote socket address */
/* FIXME: this field should no longer be present */
struct sockaddr_in sin;
uint16_t local_port; /* Local port, in network byte order */
int tcp_state; /* TCP state */
int tcp_lstate; /* Last TCP state */
uint32_t snd_una; /* Lowest unacked byte on snd stream */
uint32_t snd_win; /* Offered by remote end */
uint32_t rcv_nxt; /* Next expected byte on rcv stream */
uint32_t rcv_win; /* Advertised to receiver */
uint8_t tcp_flags; /* TCP header flags */
struct list_head list; /* List of TCP connections */
struct pk_buff *tx_pkb; /* Transmit packet buffer */
struct retry_timer timer; /* Retransmission timer */
struct tcp_operations *tcp_op; /* Operations table for connection */
};
/** Retry timer values */
#define MAX_RETRANSMITS 3
/**
* Connection closed status codes
*/
#define CONN_SNDCLOSE 0
#define CONN_RESTART 1
#define CONN_TIMEOUT 2
#define CONN_RCVCLOSE 3
/**
* A TCP header
*/
struct tcp_header {
uint16_t src; /* Source port */
uint16_t dest; /* Destination port */
uint32_t seq; /* Sequence number */
uint32_t ack; /* Acknowledgement number */
uint8_t hlen; /* Header length (4), Reserved (4) */
uint8_t flags; /* Reserved (2), Flags (6) */
uint16_t win; /* Advertised window */
uint16_t csum; /* Checksum */
uint16_t urg; /* Urgent pointer */
};
/**
* TCP masks
*/
#define TCP_MASK_HLEN 0xf0
#define TCP_MASK_FLAGS 0x3f
/**
* TCP flags
*/
#define TCP_URG 0x20
#define TCP_ACK 0x10
#define TCP_PSH 0x08
#define TCP_RST 0x04
#define TCP_SYN 0x02
#define TCP_FIN 0x01
extern struct tcpip_protocol tcp_protocol;
extern void tcp_init_conn ( struct tcp_connection *conn );
extern int tcp_connect ( struct tcp_connection *conn );
extern int tcp_connectto ( struct tcp_connection *conn,
struct sockaddr_tcpip *peer );
extern int tcp_listen ( struct tcp_connection *conn, uint16_t port );
extern int tcp_senddata ( struct tcp_connection *conn );
extern int tcp_close ( struct tcp_connection *conn );
extern int tcp_send ( struct tcp_connection *conn, const void *data,
size_t len );
#endif /* USE_UIP */
#endif /* _GPXE_TCP_H */
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